Vulnerability-Lookup

FKIE_CVE-2021-21240

Vulnerability from fkie_nvd - Published: 2021-02-08 20:15 - Updated: 2026-06-17 03:35

Severity

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

httplib2 is a comprehensive HTTP client library for Python. In httplib2 before version 0.19.0, a malicious server which responds with long series of "\xa0" characters in the "www-authenticate" header may cause Denial of Service (CPU burn while parsing header) of the httplib2 client accessing said server. This is fixed in version 0.19.0 which contains a new implementation of auth headers parsing using the pyparsing library.

References

URL	Tags
security-advisories@github.com	https://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc	Patch, Third Party Advisory
security-advisories@github.com	https://github.com/httplib2/httplib2/pull/182	Patch, Third Party Advisory
security-advisories@github.com	https://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m	Exploit, Mitigation, Third Party Advisory
security-advisories@github.com	https://pypi.org/project/httplib2	Product, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/httplib2/httplib2/pull/182	Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m	Exploit, Mitigation, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108	https://pypi.org/project/httplib2	Product, Third Party Advisory

Impacted products

	Vendor	Product	Version
	httplib2_project	httplib2	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "httplib2",
          "vendor": "httplib2",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.19.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:httplib2_project:httplib2:*:*:*:*:*:python:*:*",
              "matchCriteriaId": "D5BA135E-6889-4A5D-88F6-1AD4DBC498BE",
              "versionEndExcluding": "0.19.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "httplib2 is a comprehensive HTTP client library for Python. In httplib2 before version 0.19.0, a malicious server which responds with long series of \"\\xa0\" characters in the \"www-authenticate\" header may cause Denial of Service (CPU burn while parsing header) of the httplib2 client accessing said server. This is fixed in version 0.19.0 which contains a new implementation of auth headers parsing using the pyparsing library."
    },
    {
      "lang": "es",
      "value": "httplib2 es una biblioteca cliente HTTP completa para Python.\u0026#xa0;En httplib2 anterior a la versi\u00f3n 0.19.0, un servidor malicioso que responde con una larga serie de caracteres \"\\xa0\" en el encabezado \"www-authenticate\" puede causar una Denegaci\u00f3n de Servicio (CPU quemada mientras analiza el encabezado) del cliente httplib2 que accede a dicho servidor.\u0026#xa0;Esto se corrigi\u00f3 en la versi\u00f3n 0.19.0, que contiene una nueva implementaci\u00f3n de an\u00e1lisis de encabezados de autenticaci\u00f3n usando la biblioteca pyparsing"
    }
  ],
  "id": "CVE-2021-21240",
  "lastModified": "2026-06-17T03:35:06.433",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 5.0,
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-02-08T20:15:12.197",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/pull/182"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Mitigation",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Product",
        "Third Party Advisory"
      ],
      "url": "https://pypi.org/project/httplib2"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/commit/bd9ee252c8f099608019709e22c0d705e98d26bc"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/pull/182"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mitigation",
        "Third Party Advisory"
      ],
      "url": "https://github.com/httplib2/httplib2/security/advisories/GHSA-93xj-8mrv-444m"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Product",
        "Third Party Advisory"
      ],
      "url": "https://pypi.org/project/httplib2"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

CVE-2021-21240 (GCVE-0-2021-21240)

Vulnerability from cvelistv5 – Published: 2021-02-08 19:45 – Updated: 2024-08-03 18:09

Title

Regular Expression Denial of Service in httplib2

Summary

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/httplib2/httplib2/security/adv…	x_refsource_CONFIRM
https://github.com/httplib2/httplib2/pull/182	x_refsource_MISC
https://github.com/httplib2/httplib2/commit/bd9ee…	x_refsource_MISC
https://pypi.org/project/httplib2	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
httplib2	httplib2	Affected: < 0.19.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
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          "dateUpdated": "2024-08-03T18:09:14.827Z",
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          },
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            "url": "https://github.com/httplib2/httplib2/pull/182"
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          },
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              "x_transferred"
            ],
            "url": "https://pypi.org/project/httplib2"
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        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "httplib2",
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          "versions": [
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      ],
      "metrics": [
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.